Hollow, rotatable, cylindrical drums are often used in the asphalt industry and in other industries for heating or mixing bulk materials. These drums are typically supported on a base by a plurality of support rings, which encircle the drum. Usually, there is a mounting arrangement which fixes the support ring to the drum. There are often problems with these mounting arrangements, because the drum is often rapidly heated and cooled, causing it to expand and contract relative to the support ring. Depending upon the mounting arrangement used, the expansion and contraction of the drum relative to the support ring may cause mounting bolts to pull free, may cause welds to fail, and/or may cause the drum to distort.
U.S. Pat. No. 4,365,031 issued to Kirchoff describes one attempt at ameliorating problems related to expansion and contraction of the drum relative to the support rings. In that reference, wedges are mounted to both the drum and support ring, and the drum is supported on the ring by the inclined surfaces of the wedges. There is a radial gap between the wedges mounted on the drum and the support ring, so that the drum can expand and the drum wedges can shift radially outwardly without pressing against the inside of the support ring. However, there are several problems with this reference that are ameliorated by the present invention.
First, if it is necessary to remove the ring of Kirchoff to repair it, it is difficult to remove and cannot be removed without losing the alignment between the ring and the drum. Second, the Kirchoff design requires substantial labor to cut the metal pieces into wedge shapes, and, because the pieces have to be cut, the final finish would be rough, which does not provide good surface contact. This leads to plastic deformation, which increases the gap between the wedges, causing the drum to be eccentric with the support ring, which adversely affects the drive alignment. Third, the Kirchoff design requires many wedge-shaped pieces to be mounted on the ring and the drum, which involves substantial labor and material expense. Fourth, the Kirchoff design makes it difficult to install the ring on the drum so as to ensure proper alignment of all the wedges.